ethyl 6-hydroxy-2-hexynoate

dimethyl [3-(5-methyl-2-furyl)-2-oxopropyl]phosphonate

butyl 4-({2-[(2R)-2-(hydroxymethyl)-5-oxo-1-pyrrolidinyl]ethyl}thio)butanoate

butyl 4-({2-[(2R)-2-formyl-5-oxo-1-pyrrolidinyl]ethyl}thio)butanoate

ethyl 2-(5-methylfuran-2-yl)acetate